The benzotriazoles have long been an important class of UV absorbers and have gained wide commercial importance and acceptance for many industrial applications. The prior art is replete with references to their manufacture and utility. However, as requirements become ever more stringent and demanding, the search for still more stable and durable benzotriazoles continues. The gradual phase out of HAPS solvents, such as xylene, because of environmental concerns and their replacement with non-HAPS solvents, such as esters, ethers or ketones, and increased durability requirements for automotive coatings make this search more urgent. Indeed, the automotive industry is most concerned about UVA losses from automotive paints and coatings as seen in the publication by J. L. Gerlock et al., Proc. 36th Annual Tech. Sym. (Cleveland Coating Society), May 18, 1993.
Vysokomol Soedin, Ser. A, 18(3), 553 (1976) describes the linear dependence of hydrogen bond strength and photostability in benzotriazoles.
J. E. Pickett et al., Angew. Makromol. Chem. 232, 229 (1995) describe the photodegradation of benzotriazole UV absorbers in poly(methyl methacrylate) films. Structural variation generally caused only small differences in the rates of degradation unless the substitution disrupted the intramolecular hydrogen bonds which are critical for stability. Pickett et al. did not test any benzotriazoles containing both electron withdrawing and electron donating groups as in the instant invention.
J. Catalan et al., J. Am. Chem. Soc., 114, 964 (1992) and H. J. Heller, Eur. Polymer J. Suppl. 1969, 105 both suggest that a bulky substituent such as tert-butyl ortho to the hydroxy group on the phenyl ring will increase stability in highly polar systems.
The prior art leads one to the conclusion that strengthening the hydrogen bond leads to a more stable benzotriazole, but does not teach how this can be accomplished. The instant invention discloses benzotriazoles which exhibit enhanced durability, but surprisingly this enhanced durability is not always related to greater hydrogen bond strength. Indeed, compounds with enhanced durability often have weaker, not stronger hydrogen bonds.
U.S. Pat. Nos. 4,226,763; 4,278,589; 4,315,848; 4,275,004; 4,347,180; 5,554,760; 5,563,242; 5,574,166 and 5,607,987 describe selected benzotriazoles, substituted in the 3-position of the hydroxyphenyl ring by an .alpha.-cumyl group, which show very good durability in automotive coatings. These benzotriazoles represent the present state of the art. The instant invention is directed at preparing benzotriazoles which exhibit still better durability and low loss rates from the prior art benzotriazoles.
U.S. Pat. Nos. 5,278,314; 5,280,124; 5,436,349 and 5,516,914 describe red-shifted benzotriazoles. These benzotriazoles are substituted in the 3-position of the phenyl ring with an .alpha.-cumyl group and at the 5-position of the benzo ring by thio ethers, alkylsulfonyl or phenylsulfonyl moieties. Red-shifting the benzotriazoles is desirable for spectral reasons. A group at the 5-position which is also electron withdrawing provides additional benefits in low loss rates and durability as found in the instant invention. Missing from these patents are any alkylsulfones with seven or fewer carbon atoms. When such sulfonyl substituents are combined with specifically .alpha.-cumyl moieties, extremely durable compounds result which, due to the bulk of the .alpha.-cumyl moiety have sufficiently low volatility to be useful in coating and other polymer systems.
The presence of an .alpha.-cumyl or phenyl group ortho to the hydroxy group on the phenyl ring exerts a surprisingly large positive effect on benzotriazole photostability in coatings and photographic gel systems. The magnitude of this effect, particularly when compared to a tert-butyl group in that position, is well beyond prediction. The combination of both an electron withdrawing group on the benzo ring and an .alpha.-cumyl or phenyl group on the phenyl ring in the same molecule leads to extremely desirable properties in coating systems when high UV absorber permanence is critical.
Novel compounds meeting these parameters as being extremely stable in aggressive use environments constitute a first portion of this invention.
The presence of the electron withdrawing moiety at the 5-position of the benzo ring has a powerful stabilizing effect on benzotriazoles in general and is observed in other polymer systems such as polycarbonate and poly(vinyl chloride) substrates as well. However, the effect of having an .alpha.-cumyl or phenyl group ortho to the hydroxy moiety on the phenyl ring is much smaller to non-existent in some polymer systems such as polycarbonate or poly(vinyl chloride) even though critical for coating systems as described above.
In addition to being more photostable, the compounds of this invention are red-shifted, absorbing strongly in the 350-400 nm wavelength range. While such red-shifting is desirable in that a greater portion of the UV spectrum is absorbed, this can also introduce color if the absorption beyond 400 nm is significant. This can limit the use of such compounds, particularly in systems such as polycarbonate glazing applications or present difficulties in various pigmented systems.
It is found that the nature of the substituent ortho to the hydroxyl group on the phenyl ring has an unexpected impact on color imparted to the substrate by the benzotriazole. Thus, relatively subtle differences in substitution on the phenyl ring can have a large impact on the resulting color and the applicability of the benzotriazole in specific color sensitive applications. There are striking differences between having hydrogen, alkyl or .alpha.-cumyl at this 3-position.
Furthermore, it is found that, when the 5-position of the benzo ring is substituted with a trifluoromethyl group, the resulting benzotriazole not only exhibits the same or greater enhanced stability when incorporated into thermoplastic resins, but also imparts less color than related benzotriazoles substituted at the 5-position with other electron withdrawing moieties such as sulfonyl or carbonyl. These trifluoromethyl compounds also absorb strongly in the 350-400 nm wavelength range despite the low color and are extremely compatible in a wide range of substrates such as acrylic resins, hydrocarbons, polycarbonates and poly(vinyl chloride).
There are a multitude of general references to benzotriazoles having in the 5-position of the benzo ring electron withdrawing groups such as esters, amides, sulfones and the like that are not substituted in the 3-position of the phenyl ring by an .alpha.-cumyl or phenyl moiety. In many of these references the broadly described compounds are unexemplified and no teaching or appreciation taught of the positive effect on photostability described in this invention. In any event, the vast majority of these structures fall well outside the scope of instant invention.
Perfluoroalkyl, specifically trifluoromethyl, is an ideal substituent for the 5-position of the benzo ring. The prior art relevant to this substituent is very limited and exemplifies none of the instant compounds. As a result, said prior art naturally fails to point out the important advantages regarding stability, color and compatibility achievable with the 5-trifluoromethyl substituted benzotriazoles of this invention. The general, unexemplified references to alkyl substituted with halogen are acknowledged, but are clearly irrelevant to the instant invention.
German Offen. 1,670,951 describes inter alia the use of methylene (or alkylidene) bis-benzotriazoles substituted with electron withdrawing groups in polymeric resins. Especially useful are the asymmetrical compounds where only one benzotriazole moiety is substituted. Such asymmetric compounds have considerably less color.
German 116,230 provides a method of preparing benzotriazole N-oxide intermediates which can be converted into dyes and light stabilizers. The N-oxide of 5-trifluoromethyl-2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole is disclosed. This N-oxide could be reduced to the corresponding benzotriazole which is substituted at the 5-position of the phenyl ring. However, this benzotriazole is clearly outside the scope of the instant claims. Other related light stabilizer intermediates are generically disclosed in this reference, but none where ever converted to actual benzotriazole UV absorbers. The outstanding properties of such benzotriazole UV absorbers clearly went undiscovered.
Japanese Hei 3-57690 claims a color developer sheet compositions containing salicylic acid salts and benzotriazoles. Broadly described are benzotriazoles which may be substituted on the benzo ring with unspecified trihalomethyl. However, other benzotriazole ring substituents also are broadly described to include unspecified alkyl, alkoxy, aryloxy, amino, cyano, acyl, nitro and halogen. The only benzotriazoles named as typical examples are either unsubstituted on the benzo ring or substituted by chlorine. The preference is for liquid compounds. The 3-position of the phenyl ring is specified as tert-alkyl. While this reference broadly discloses a wide variety of benzotriazole derivatives in its photographic compositions many are electron donating and produce compounds which are in photostability inferior not only to the instant compounds, but also to standard unsubstituted benzotriazoles. No examples or differentiation between within this diverse array is seen. Further, while generic trihalomethyl is described, no compounds of this description are shown or further described in any way. Additionally, trichloro, tribromo and triiodo compounds are clearly outside the scope of the instant invention.
Japanese Sho 47-15210 describes resin compositions containing selected benzotriazoles substituted by a fluorinated alkyl. The generic structures allows for a fluorinated alkyl, but not necessarily perfluorinated alkyl, to be added to either or both the benzo or phenyl rings at any position (the substituents are floating in the generial formula). Non-fluorinated substituents, one on each ring, are defined as hydrogen, halogen, hydroxy, alkyl and alkoxy with no other more specific description. The exemplified resins are poly(vinyl chloride), polycarbonate, ABS and nylon. Seven compounds are specifically exemplified all outside the scope of the instant invention plus one composition containing 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole. No physical data or synthesis for any of these seven compounds are given.
The seven compounds exemplified in the Japanese reference are given below:
a. 2-(2-hydroxy-4-trifluoromethylphenyl)-2H-benzotriazole; PA1 b. 5-methyl-2-(2-hydroxy-4-trifluoromethylphenyl)-2H-benzotriazole; PA1 c. 5-methoxy-2-(2-hydroxy-4-trifluoromethylphenyl)-2H-benzotriazole; PA1 d. 5-chloro-2-(2-hydroxy-4-trifluoromethylphenyl)-2H-benzotriazole; PA1 e. 5-peroxymethoxy-2-(2-hydroxy-4-methylphenyl)-2H-benzotriazole; PA1 f. 5-perfluorooctyl-2-(2-hydroxy-4-methylphenyl)-2H-benzotriazole; and PA1 g. 5-perfluorooctyl-2-(2-hydroxy-4-trifluoromethylphenyl)-2H-benzotriazole. PA1 G.sub.1 is hydrogen or chloro, PA1 G.sub.2 is cyano, perfluoroalkyl of 1 to 12 carbon atoms, fluOrO, --CO--G.sub.3, --COOG.sub.3, --CONHG.sub.3, --CON(G.sub.3).sub.2, E.sub.3 SO-- or E.sub.3 SO.sub.2 --, PA1 G.sub.3 is hydrogen, straight or branched chain alkyl of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms, PA1 G.sub.6 is perfluoroalkyl of 1 to 12 carbon atoms, PA1 G.sub.7 is hydrogen or perfluoroalkyl of 1 to 12 carbon atoms, PA1 E.sub.1 is hydrogen, straight or branched chain alkyl of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 24 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms; or E.sub.1 is alkyl of 1 to 24 carbon atoms substituted by one or two hydroxy groups, PA1 E.sub.2 and E.sub.2 ' are independently straight or branched alkyl chain of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by one to three alkyl of 1 to 4 carbon atoms; or E.sub.2 and E.sub.2 ' are independently said alkyl of 1 to 24 carbon atoms or said alkenyl of 2 to 18 carbon atoms substituted by one or more --OH, --OCOE.sub.11, --OE.sub.4, --NCO, --NH.sub.2, --NHCOE.sub.11, --NHE.sub.4 or --N(E.sub.4).sub.2, or mixtures thereof, where E.sub.4 is straight or branched chain alkyl of 1 to 24 carbon atoms; or said alkyl or said alkenyl interrupted by one or more --O--, --NH-- or --NE.sub.4 -- groups or mixtures thereof and which can be unsubstituted or substituted by one or more --OH, --OE.sub.4 or --NH.sub.2 groups or mixtures thereof; PA1 n is 1 or 2, PA1 when n is 1, E.sub.5 is Cl, OE.sub.6 or NE.sub.7 E.sub.8, or PA1 E.sub.5 is --PO(OE.sub.12).sub.2, --OSi(E.sub.11).sub.3 or --OCO--E.sub.11, PA1 E.sub.6 is hydrogen, straight or branched chain C.sub.1 -C2.sub.4 alkyl which is unsubstituted or substituted by one or more OH, OE.sub.4 or NH2 groups, or --OE.sub.6 is --(OCH.sub.2 CH.sub.2),OH or --(OCH.sub.2 CH.sub.2),OE.sub.21 where w is 1 to 12 and E.sub.21 is alkyl of 1 to 12 carbon atoms, PA1 E.sub.7 and E.sub.8 are independently hydrogen, alkyl of 1 to 18 carbon atoms, straight or branched chain C.sub.3 -C.sub.18 alkyl which is interrupted by --O--, --S-- or --NE.sub.11 --, C.sub.5 -C.sub.12 cycloalkyl, C.sub.6 -C.sub.14 aryl or C.sub.1 -C.sub.3 hydroxylalkyl, or E.sub.7 and E.sub.8 together with the N atom are a pyrrolidine, piperidine, piperazine or morpholine ring, or PA1 E.sub.5 is --X--(Z)P--Y--E.sub.15 PA1 X is --O-- or --N(E.sub.16)--, PA1 Y is --O-- or --N(E.sub.17)--, PA1 Z is C.sub.2 -C.sub.12 -alkylene, C.sub.4 -C.sub.12 -alkylene interrupted by one to three nitrogen atoms, oxygen atoms or a mixture thereof, or is C.sub.3 -C.sub.12 -alkylene, butenylene, butynylene, cyclohexylene or phenylene, each substituted by a hydroxyl group, PA1 m is zero, 1 or 2, PA1 p is 1, or p is also zero when X and Y are --N(E.sub.16)-- and --N(E.sub.17)--, respectively, PA1 E.sub.15 is a group --CO--C(E.sub.18).dbd.C(H)E.sub.19 or, when Y is --N(E.sub.17)--, forms together with E.sub.17 a group --CO--CH.dbd.CH--CO--, wherein E.sub.18 is hydrogen or methyl, and E.sub.19 is hydrogen, methyl or --CO--X--E.sub.20, wherein E.sub.20 is hydrogen, C.sub.1 -C.sub.12 -alkyl or a group of the formula ##STR2## PA1 when n is 2, E.sub.5 is one of divalent radicals --O--E.sub.9 --O-- or --N(E.sub.11)--E.sub.10 --N(E.sub.11)--, PA1 E.sub.9 is C.sub.2 -C.sub.8 alkylene, C.sub.4 -C.sub.8 alkenylene, C.sub.4 alkynylene, cyclohexylene, straight or branched chain C.sub.4 -C.sub.10 alkylene which is interrupted by --O-- or by --CH.sub.2 --CHOH--CH.sub.2 --O--E.sub.14 --O--CH.sub.2 --CHOH--CH.sub.2 --, PA1 E.sub.10 being straight or branched chain C2-C.sub.12 alkylene which may be interrupted by --O--, cyclohexylene, or ##STR3## PA1 E.sub.14 is straight or branched chain C.sub.2 -C.sub.8 alkylene, straight or branched chain C.sub.4 -C.sub.10 alkylene which is interrupted by --O--, cycloalkylene, arylene or ##STR4## PA1 E.sub.11 is hydrogen, straight or branched chain C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl, straight or branched chain C.sub.2 -C.sub.18 alkenyl, C.sub.6 -C.sub.14 aryl or C.sub.7 -C.sub.15 aralkyl, PA1 E.sub.12 is straight or branched chain C.sub.1 -C.sub.18 alkyl, straight or branched chain C.sub.3 -C.sub.18 alkenyl, C.sub.5 -C.sub.10 cycloalkyl, C.sub.6 -C.sub.16 aryl or C.sub.7 -C.sub.15 aralkyl, PA1 E.sub.13 is H, straight chain or branched C.sub.1 -C.sub.18 alkyl which is substituted by --PO(OR.sub.12).sub.2, phenyl which is unsubstituted or substituted by OH, C.sub.7 -C.sub.15 aralkyl or --CH.sub.2 OE.sub.12, PA1 E.sub.3 is alkyl of 1 to 20 carbon atoms, hydroxyalkyl of 2 to 20 carbon atoms, alkenyl of 3 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylaLkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or said aryl substituted by one or two alkyl of 1 to 4 carbon atoms or 1,1,2,2-tetrahydroperfluoroalkyl where the perfluoroalkyl moiety is of 6 to 16 carbon atoms, PA1 L is alkylene of 1 to 12 carbon atoms, alkylidene of 2 to 12 carbon atoms, benzylidene, p-xylylene, .alpha.,.alpha.,.alpha.',.alpha.'-tetramethyl-m-xylylene or cycloalkylidene, and PA1 T is --SO--, --SO.sub.2 --, --SO--E--SO--, --SO.sub.2 --E--SO2--, --CO--, --CO--CO--, --CO--CH.sub.2 --CO--, --CO--E--CO--, --COO--E--OCO-- or --CO--NG.sub.5 --E--NG.sub.5 --CO--, PA1 where E is alkylene of 2 to 12 carbon atoms, cycloalkylene of 5 to 12 carbon atoms, or alkylene interrupted or terminated by cyclohexylene of 8 to 12 carbon atoms; PA1 G.sub.5 is G.sub.3 or hydrogen, and PA1 with the proviso that when T is --SO--, --SO.sub.2 --, --SO--E--SO-- or --SO.sub.2 --E--SO.sub.2 --, E.sub.1 is not hydrogen, straight or branched chain alkyl of 1 to 24 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms; or when E.sub.3 is alkyl of 1 to 6 carbon atoms, E.sub.1 is not hydrogen or phenyl, and the sum of the carbon atoms of E.sub.1 plus E.sub.2 is equal to or greater than 8; and when E.sub.3 is alkyl of 8 to 18 carbon atoms or alkenyl of 2 to 24 carbon atoms, E.sub.1 is not hydrogen, straight or branched chain of 1 to 24 carbon atoms, cycloalkyl of 5 to 12 carbon atoms or phenylalkyl of 7 to 15 carbon atoms; or when G.sub.2 is cyano, --CO--G.sub.3. --CONHG.sub.3, --CON(G.sub.3).sub.2 or --COOG.sub.3, then E.sub.1 is phenyl or phenylalkyl of 7 to 15 carbon atoms, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms; or when E.sub.1 is hydrogen, E.sub.2 is not methyl. PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is cyano, CF.sub.3 --, fluoro, --CO--G.sub.3 or E.sub.3 SO.sub.2 --, PA1 G.sub.3 is straight or branched chain alkyl of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms, PA1 E.sub.1 is phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms, PA1 E.sub.2 is straight or branched alkyl chain of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 3 alkyl of 1 to 4 carbon atoms; or E.sub.2 is said alkyl of 1 to 24 carbon atoms or said alkenyl of 2 to 18 carbon atoms substituted by one or more --OH, --OCOE.sub.11, --OE.sub.4, --NCO, --NH.sub.2, --NHCOE.sub.11, --NHE.sub.4 or --N(E.sub.4).sub.2, or mixtures thereof, where E.sub.4 is straight or branched chain alkyl of 1 to 24 carbon atoms; or said alkyl or said alkenyl interrupted by one or more --O--, --NH-- or --NE.sub.4 -- groups or mixtures thereof and which can be unsubstituted or substituted by one or more --OH, --OE.sub.4 or --NH.sub.2 groups or mixtures thereof; PA1 E.sub.3 is alkyl of 1 to 20 carbon atoms, hydroxyalkyl of 2 to 20 carbon atoms, alkenyl of 3 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, aryl of 6 to 10 carbon atoms or said aryl substituted by one or two alkyl of 1 to 4 carbon atoms or 1,1,2,2-tetrahydroperfluoroalkyl where the perfluoroalkyl moiety is of 6 to 16 carbon atoms; or PA1 is a compound of formula I wherein, PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is CF.sub.3 --, fluoro or E.sub.3 SO.sub.2 --, PA1 E.sub.1 is hydrogen or straight or branched alkyl of 4 to 24 carbon atoms, PA1 E.sub.2 is as defined above, and PA1 E.sub.3 is straight or branched chain alkyl of 1 to 7 carbon atoms, PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is is CF.sub.3 -- or fluoro, PA1 E.sub.1 is hydrogen, straight or branched alkyl of 4 to 24 carbon atoms or phenylalkyl of 7 to 15 carbon atoms, PA1 E.sub.5 is --OE.sub.6 or --NE.sub.7 E.sub.8, or PA1 E.sub.5 is EQU --X--(Z).sub.p --Y--E.sub.15 PA1 X is --O-- or --N(E.sub.16)--, PA1 Y is --O-- or --N(E.sub.17)--, PA1 Z is C.sub.2 -C.sub.12 -alkylene, C.sub.4 -C.sub.2 -alkylene interrupted by one to three nitrogen atoms, oxygen atoms or a mixture thereof, or is C.sub.3 -C.sub.12 -alkylene, butenylene, butynylene, cyclohexylene or phenylene, each substituted by a hydroxyl group, PA1 m is 0, 1, 2 or 3, PA1 p is 1, or p is also zero when X and Y are --N(E16)-- and --N(E.sub.17)--, respectively, PA1 E.sub.15 is a group --CO--C(E.sub.18).dbd.C(H)E.sub.19 or, when Y is --N(E.sub.17)--, forms together with E.sub.17 a group --CO--CH.dbd.CH--CO--, wherein E.sub.18 is hydrogen or methyl, and E.sub.19 is hydrogen, methyl or --CO--X--E.sub.20, wherein E.sub.20 is hydrogen, C.sub.1 -C.sub.12 -alkyl or a group of the formula. ##STR7## PA1 G.sub.6 is CF.sub.3, PA1 G.sub.7 is hydrogen or CF.sub.3, PA1 E.sub.2 and E.sub.2 ' are independently straight or branched alkyl chain of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 3 alkyl of 1 to 4 carbon atoms; and PA1 L is alkylene of 1 to 12 carbon atoms, alkylidene of 2 to 12 carbon atoms, benzylidene, p-xylylene, .alpha.,.alpha.,.alpha.',.alpha.'-tetramethyl-m-xylylene or cycloalkylidene. PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is CF.sub.3 --, PA1 E.sub.1 is phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 4 alkyl of 1 to 4 carbon atoms, PA1 E.sub.2 is straight or branched alkyl chain of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 3 alkyl of 1 to 4 carbon atoms; or E.sub.2 is said alkyl of 1 to 24 carbon atoms or said alkenyl of 2 to 18 carbon atoms substituted by one or more --OH, --OCOE.sub.11, --NH.sub.2 or --NHCOE.sub.11, or mixtures thereof; or said alkyl or said alkenyl interrupted by one or more --O-- which can be unsubstituted or substituted by one or more --OH groups; or PA1 is a compound of formula I wherein, PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is CF.sub.3 --, PA1 E.sub.1 is hydrogen, straight or branched alkyl of 4 to 24 carbon atoms or phenylaikyl of 7 to 15 carbon atoms, and PA1 E.sub.2 is as defined above. PA1 G.sub.1 is hydrogen, PA1 G.sub.2 is CF.sub.3 --, PA1 E.sub.1 is hydrogen, straight or branched alkyl of 4 to 24 carbon atoms or phenylalkyl of 7 to 15 carbon atoms, PA1 E.sub.5 is --OE.sub.6 or --NE.sub.7 E.sub.8 where PA1 E.sub.6 is hydrogen, straight or branched chain C.sub.1 -C.sub.24 alkyl which is unsubstituted or substituted by one or more OH groups, or --OE.sub.6 is --(OCH.sub.2 CH.sub.2).sub.w OH or --(OCH.sub.2 CH.sub.2).sub.w OE.sub.21 where w is 1 to 12 and E.sub.21 is alkyl of 1 to 12 carbon atoms, and PA1 E.sub.7 and E.sub.8 are independently hydrogen, alkyl of 1 to 18 carbon atoms, straight or branched chain C.sub.3 -C.sub.18 alkyl which is interrupted by --O--, --S-- or --NE.sub.11 --, C.sub.5 -C.sub.12 cycloalkyl, C.sub.6 -C.sub.14 aryl or C.sub.1 -C.sub.3 hydroxylalkyl, or E.sub.7 and E.sub.8 together with the N atom are a pyrrolidine, piperidine, piperazine or morpholine ring. PA1 G.sub.6 is CF.sub.3, PA1 G.sub.7 is hydrogen or CF.sub.3, PA1 E.sub.2 and E.sub.2 ' are independently straight or branched alkyl chain of 1 to 24 carbon atoms, straight or branched chain alkenyl of 2 to 18 carbon atoms, cycloalkyl of 5 to 12 carbon atoms, phenylalkyl of 7 to 15 carbon atoms, phenyl, or said phenyl or said phenylalkyl substituted on the phenyl ring by 1 to 3 alkyl of 1 to 4 carbon atoms; and PA1 L is methylene. PA1 (a) an organic material subject to thermal, oxidative or light-induced degradation, and PA1 (b) an effective stabilizing amount of a compound of formula I, II, III or IV. PA1 a) radical polymerisation (normally under high pressure and at elevated temperature). PA1 b) catalytic polymerisation using a catalyst that normally contains one or more than one metal of groups IVb, Vb, Vlb or VIII of the Periodic Table. These metals usually have one or more than one ligand, typically oxides, halides, alcoholates, esters, ethers, amines, alkyls, alkenyls and/or aryls that may be either .pi.- or .sigma.-croordinated. These metal complexes may be in the free form or fixed on substrates, typically on activated magnesium chloride, titanium(III) chloride, alumina or silicon oxide. These catalysts may be soluble or insoluble in the polymerisation medium. The catalysts can be used by themselves in the polymerisation or further activators may be used, typically metal alkyls, metal hydrides, metal alkyl halides, metal alkyl oxides or metal alkyloxanes, said metals being elements of groups Ia, IIa and/or IIIa of the Periodic Table. The activators may be modified conveniently with further ester, ether, amine or silyl ether groups. These catalyst systems are usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or single site catalysts (SSC).
There are several distinct differences between the disclosure of this Japanese reference and the instant invention. First all the exemplified compounds of the Japanese reference are substituted in the 4-position of the phenyl ring by groups other than hydrogen. The reference allows for substitution of either fluoroalkyl or fluoroalkoxy on any site on either ring as a means of providing for an improved UV absorber. Data given in this application shows this teaching to be inaccurate. Electron withdrawing moities on the phenyl ring as found in a, b, c, d, and g above, are shown to provide compounds with less durability than unsubstituted derivatives as seen in Example 77. Spectral coverage in the red region is also compromised as seen in Example 74. Significantly, 2-(2-hydroxy-5-trifluoromethylphenyl)-2H-benzotriazole which is very similar to compound a above, is blue-shifted relative to benzotriazoles such as 2-(2-hydroxy-5-methylphenyl)-2H-benzotriazole as seen in Example 74. Blue-shifting is undesirable since the need for coverage in the 350-400 nm region is critical for UV absorbers.
An electron donating group at the 5-position of the benzo ring such as the ether compound c above reduces stability as seen in Example 77. While the Japanese reference states fluoroalkyl or fluoroalkoxy radical leads to enhanced stability under light, the instant invention shows that it is the electron withdrawing nature of the group at the 5-position on the benzo ring that confers greater photostability. No such inference in seen in the Japanese reference, and the electron donating ether even a fluorinated ether is counterindicated for enhanced stability.
Furthermore, all examples in the Japanese reference bear only one substituent on the phenyl ring and that is specifically at the 4-position. The instant invention specifically claims only hydrogen at the 4-position as substitution at the 4-position brings undesirable consequences for the use of these compounds in many applications. The compound f is the closest to the instant invention, but it is substituted by a 4-methyl group. As seen in Example 79, substitution of the phenyl ring by an electron donating group at the 5-position diminishes photostability in coatings. Pickett et al. report the same loss of durability for such compounds in thermoplastics. The electron donating characteristics of methyl are less pronounced, but are still similar to alkoxy. The .sigma..sub.p value, as measure of the electronic effect of substituents for aromatic methoxy substitution is -0.27 while for methyl is -0.17 (March J. "Advanced Organic Chemistry", 2nd Ed. (1977), McGraw-Hill, New York, p 253).
While the generic disclosure of the Japanese reference overlaps formula I of the instant application no such compound is specifically disclosed in the Japanese reference. As mentioned above, all examples of the Japanese reference are substituted at the 4-position of the phenyl ring, most contain the electron withdrawing CF.sub.3 group at the 4-position. Compounds of the instant invention explicitly denote hydrogen at the 4-position of the phenyl ring for reasons including color and stability, and expressly designate the 5-position of the benzo ring as the location of the perfluoroalkyl moiety for reasons of stability and spectral coverage.
U.S. Pat. Nos. 3,936,305; 4,681,905; 4,684,679; 4,684,680 and 5,108,835 teach the 2,2'-methylene-bis[4-hydrocarbyl-6-(benzotriazol-2-yl)phenols] having high molar activities and low volatility. In addition Unites States Patent Nos. 5,292,890 and 5,360,850 teach that asymmetrical bis-benzotriazoles display higher solubility in organic non-polar solvents that the symmetrical dimers made from the same benzotriazole monomer.
U.S. Pat. No. 5,166,355 describes a process for making 2,2'-methylene-bis[6-(benzotriazol-2-yl)-4-hydrocarbylphenol] or 5,5'-methylene-bis(2-hydroxy-4-alkoxybenzophenone) using bis(dialkylamino)methane.
Related bis-benzotriazoles of the instant invention substituted at one or at both of the benzotriazole rings by perfluoroalkyl are unknown and provide the same improvement to these bis-benzotriazoles as mentioned above, namely enhanced durability and broader spectral coverage. Substitution of only one of the benzotriazole moieties in these bis-benzotriazoles by perfluoroalkyl gives the additional advantage of much lower color than the disubstituted compound, indeed nearly to the color of the bis-benzotriazole not substituted by perfluoroalkyl.